Corneoscleral Rims Research Articles

Chikungunya Virus Infection of Corneal Grafts

Chikungunya virus (CHIKV) is an arbovirus with a high potential to spread globally. We investigated whether CHIKV is transmittable via corneal grafts. Serum specimens from 69 potential corneal donors living in La Réunion during the 2005–2006 outbreak of CHIKV infection were screened for anti-CHIKV antibodies. Serum specimens and corneoscleral rims were subjected to quantitative reverse-transcription real-time polymerase chain reaction (qRT-PCR) for detection of CHIKV. CHIKV isolation and immunolabeling were performed on eye tissue specimens. Viral transmission via the ocular route was assessed in an animal model of human CHIKV infection. Twelve apparently uninfected donors were viremic and/or positive for immunoglobulin M (IgM) and/or immunoglobulin G. Eye tissue specimens from 12 donors who were or were not viremic and were or were not seropositive were investigated. qRT-PCR detected CHIKV RNA in corneoscleral rims from 4 patients: 1 patient was viremic, 2 were viremic and IgM positive, and 1 was IgM positive. Infectious CHIKV was isolated from all qRT-PCR–positive samples, and antigens were detected in corneal and scleral specimens, the iris, the ciliary body, and oculomotor muscles. One-third of eligible corneas (4 of 12) from donors apparently uninfected with CHIKV were infected with CHIKV during the study period. CHIKV infects the human cornea and can be transmitted via the ocular route. In the absence of systematic CHIKV screening in donors, cornea donation should be banned in areas where CHIKV circulates.

Corneal collagen crosslinking in vitro: Inhibited regeneration of human limbal epithelial cells after riboflavin–ultraviolet-A exposure

To assess the hypothesis that during corneal crosslinking (CXL) treatment, riboflavin and ultraviolet-A (UVA) may have a toxic effect on human limbal epithelial cells. Center for Eye Research, Department of Ophthalmology, Oslo University Hospital Ullevål, Oslo, Norway. Experimental study. In this vitro study, limbal biopsies from corneoscleral rims collected after corneal transplantation were treated with the following combinations: riboflavin-UVA, riboflavin only, or UVA only; a control group received no treatment. After 3 weeks of cell culture, outgrowth of epithelium from the biopsies was evaluated by measuring the area of cell expansion and the number of cell layers. The explanted biopsies were analyzed for proliferation using immunohistochemistry marker Ki-67 and for apoptosis using the terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) assay. The mean outgrowth from the biopsies was 2.25 mm(2) ± 6.90 (SD) in the riboflavin-UVA group, 181.4 ± 94.8 mm(2) in the riboflavin-only group, 128.5 ± 129.5 mm(2) in the UVA-only group, and 176.2 ± 114.0 mm(2) in the control group. There were no statistically significant between-group differences in the number of cell layers except in the riboflavin-UVA group, in which no cells were found. Detection of apoptosis with the TUNEL-assay was found in the riboflavin-UVA group only (4/5 sections). The proliferation marker Ki-67 was positive in some sections in all groups. Cytotoxicity and reduced cell expansion of human limbal epithelial cells occurred after riboflavin-UVA treatment in vitro, emphasizing the importance of avoiding riboflavin-UVA on the limbus during CXL.

The effect of gravitational force on limbal stem cell growth

AimTo evaluate the effect of gravity on corneal epithelial cell migration in vitro.MethodsFourteen donor peripheral corneoscleral rims were used. Twenty explants were chosen of which 10 were placed vertically and...

Impact of Eye Bank Lamellar Tissue Cutting for Endothelial Keratoplasty on Bacterial and Fungal Corneoscleral Donor Rim Cultures After Corneal Transplantation

To determine if the lamellar cut of donor tissue for endothelial keratoplasty (EK) by an eye bank facility is associated with a change in the prevalence of positive bacterial or fungal donor rim cultures after corneal transplantation. A retrospective review was conducted of bacterial and fungal cultures of donor rims used for corneal transplantation at a tertiary eye care center from January 1, 2003, to December 31, 2008, with tissue provided by a single eye bank. The cases were divided into 2 groups. Group 1 ("no-cut") included keratoplasty procedures in which a lamellar cut was not performed. Group 2 ("precut") included EK procedures in which a 4-hour period of prewarming of tissue followed by a lamellar cut was performed in the eye bank before tissue delivery to the operating surgeon. There were 351 donor rim cultures in group 1 and 278 in group 2. Bacterial cultures were positive in 30 donor rims (8.5%) in group 1 and 13 (4.7%) in group 2 (P = 0.058). Positive bacterial cultures were not associated with any postoperative infections. Fungal cultures were positive in 8 donor rims (2.3%) in group 1 and 7 (2.5%) in group 2 (P = 1.0). Positive fungal cultures were associated with 2 cases (13.3%) of postoperative fungal infections. Corneal donor tissue can be precut for EK by trained eye bank personnel without an increased risk of bacterial or fungal contamination.

Donor cornea transfer from Optisol GS to organ culture storage: a two‐step procedure to increase donor tissue lifespan

PurposeStorage time for donor corneas in Optisol GS is limited compared to Eye Bank Organ Culture (EBOC). We here examine the epithelium on donor corneoscleral rims after primary storage in Optisol GS and subsequent incubation in EBOC.MethodsMorphology was monitored by light and electron microscopy, expression of phenotypic and genotypic markers by immunohistochemistry and RT-PCR and changes in oxidative lipid and DNA damage by ELISA and COMET assay.ResultsA prominent loss of cells was observed after storage in Optisol GS. After maintenance in EBOC, spreading apical cells were Occludin+, while the staining for E-cadherin and Connexin-43 was less intense. There were an upregulation of Occludin and a downregulation of E-cadherin and Connexin-43. Eye Bank Organ Culture was associated with an ongoing proliferative activity and a downregulation of putative progenitor/stem cell marker ABCG2 and p63. Staining for 8-OHdG and Caspase-3 did not increase, while levels of malondialdehyde and number of DNA strand breaks and oxidized bases increased.ConclusionsThis dual procedure should be pursued as an option to increase the storage time and the pool of available donor corneas. The observed downregulation of markers associated with stemness during EBOC is relevant considering the potential use of donor epithelium in the treatment of ocular surface disorders.

Decellularization of porcine corneas and repopulation with human corneal cells for tissue‐engineered xenografts

To evaluate the potential use of decellularized porcine corneas (DPCs) as a carrier matrix for cultivating human corneal cells in tissue engineering. Corneal cells were isolated from human corneoscleral rims. Porcine corneas were decellularized using hypotonic tris buffer, ethylene diamine tetra-acetic acid (EDTA, 0.1%), aprotinin (10 KIU/ml) and 0.3% sodium dodecyl sulphate. Haematoxylin-eosin (HE) and 4,6-diamidino-2-phenylindole (DAPI) staining were performed to confirm removal of the corneal cells. Quantitative analysis was performed to determine levels of desoxyribonucleic acid (DNA) using DNA Purification Kit (Fermentas, St. Leon-Rot, Germany). Alcian blue staining was carried out to analyse the structure of the extracellular matrix (ECM). Corneal stromal cells were injected into the DPCs; limbal corneal epithelial cells and corneal endothelial cells were seeded onto the anterior and posterior surfaces of the DPCs, respectively. Evaluation was undertaken at days 14 and 30. The phenotypical properties of the cultivated corneal cells were investigated using Immunolocalization of type I collagen, keratocan, lumican, cytokeratin 3 (AE5) and type VIII collagen. Haematoxylin-eosin and DAPI staining showed efficient elimination of porcine corneal cells, whereas alcian blue confirmed gross preservation of the ECM. The quantitative analysis of the DNA content showed a significant reduction (mean before decellularization: 75.45 ± 13.71 ng/mg; mean after decellularization: 9.87 ± 2.04 ng/mg, p < 0.001). All three types of corneal cells were efficiently cultured and expanded on the DPCs. Decellularized porcine corneas might serve as a potential scaffold for tissue engineering of the cornea, possibly providing xenogenic substrate for corneal transplantation.

Culture of Corneal Limbal Epithelial Stem Cells: Experience From Benchtop to Bedside in a Tertiary Care Hospital in India

To standardize the technique of ex vivo culture of limbal epithelial stem cells (LESCs) using locally available adapted methods and evaluate the outcome of transplantation in patients with limbal stem cell deficiency. Limbal tissue specimens were isolated from cadaveric corneoscleral rims, living related donors, or contralateral eye of the patients. Harvested tissue was cultured on denuded human amniotic membrane (dHAM) using various techniques to stabilize dHAM. The optimization of in vitro culture conditions was achieved by modifications in culture media (culture media 1 and 2). The LESCs were cultured in both types of media for 2 weeks, and growth patterns were observed. Expanded cells were further characterized by immunocytochemistry (K3/12, K19, and ABCG2) and reverse transcriptase polymerase chain reaction (K12, Cx43, Pax6, ABCG2, p63, and K19). The cultivated epithelium was transplanted in 50 patients with total and partial limbal stem cell deficiencies. Stabilization of dHAM was successfully achieved using coverslips. The outgrowth was observed within 1-3 days of culture using both types of culture media (P = 0.20), but cultures in culture medium 1 reached confluency faster than cultures in culture medium 2 (P = 0.0004). Histopathological analysis showed multilayer formation and immunostaining, and reverse transcriptase polymerase chain reaction data confirmed the expression of both stem cell markers (K19, p63, and ABCG2) and differentiation markers (K3, K12, and Cx43). Patients who had undergone limbal stem cell transplantation showed a stable ocular surface with improved visual acuity over a long-term follow-up period. LESCs were successfully cultured using locally available adapted methods, and their clinical benefits verified by transplantation.

Mechanical reinforcement of the cornea with an intrastromal in‐situ photo‐polymerised implant.

AbstractPurpose A photo‐polymerisable hydrophilic material (PEG/Irg) has been previously evaluated in terms of biocompatibility and toxicity in a series of laboratory animals. It was the purpose of this study to evaluate the bio‐mechanical effect of lamellar implants created from PEG/Irg in porcine cadaver eyes.Methods Twenty porcine corneas where removed along with a 3 mm corneoscleral rim, de‐epithelialised and mounted on an artificial anterior chamber. The pressure was maintained at 22 mmHg hydrostatically. In each cornea, a circular lamellar pocket (7mm diameter) was created manually. Thirty microliters of PEG/Irg in liquid form were injected in each pocket. A rigid contact lens was pressed on top of the cornea and the excessive quantity of PEG/Irg was leaked out of the pocket. The cornea was then irradiated with UV light (390nm, 4mW/cm2) and the PEG/Irg underwent a polymerization and the associated phase transition to form a rigid film. Mechanical measurements were performed by means of a purposely‐developed device featuring a stepping motor and a load cell. By keeping the pressure constant the role of corneal stiffness is isolated. The force as a function of indentation was recorded for each specimen before and after the in‐situ creation of the PEG/Irg film.Results The mean slope of force versus indentation for the reinforced group was 166.72 (±74.14) and the mean slope for the non‐reinforced group was 116.94 (±21.16). The two‐tailed P value equals 0.0033, equally meaning that the difference between those two groups was statistically different.Conclusion According to the results, there was a significant biomechanical reinforcement of the cornea following the in‐situ creation of the polymer film.

Conjunctival swabs and corneoscleral rim cultures from corneal transplantation donors as possible early indicators for posttransplant endopthalmitis

To determine by microbiological examinations the rate of conjunctiva and corneoscleral rim contamination of cadaver donor tissues. A prospective review of culture results for 98 cadaver donor conjunctival swabs [mean age 76.4 ± 12.9 years (±SD)]. Transplant patients were evaluated both before and after disinfection with gentamicin. Individual parameters evaluated included detection rates of bacteria, variety of detected bacteria, time interval from donor death to tissue harvest and age of donors. Before disinfection, 60 out of 98 conjunctival swabs exhibited microbial growth, while only 36 out of 98 exhibited growth after disinfection (p = 0.0006). Longer intervals between death and tissue harvest were associated with higher positive microbial growth rates. Prior to disinfection, culture-positive donors (74.1 ± 13.6 years) were significantly younger than culture-negative donors (79.8 ± 10.8 years) (p = 0.024). Positive donor rim cultures were noted in 2 out of the 22 corneal transplantations. Microorganisms isolated from the corneal grafts matched those found in the conjunctiva. It is recommended that the corneoscleral buttons be removed as soon as possible. Cultures of conjunctival swabs collected from donors after disinfection may be useful in determining treatment for postoperative infections occurring after corneal transplantation.

Central thickening of the donor posterior corneal disc in femtosecond-laser-assisted Descemet’s stripping endothelial keratoplasty

A 49-year-old man complained of progressive visual disturbance oculus dexter (OD), which commenced 1 year earlier. He had undergone cataract extraction OD 20 years earlier and presented with recurrent uveitis over the 5 years before his latest presentation. Best corrected visual acuity (BCVA) OD was 20/100 and intraocular pressure (IOP) was 16 mmHg. Slit-lamp microscopy showed a superiorly distorted iris, aphakia, diffuse corneal edema, and Descemet’s folds. Aphakic bullous keratopathy was diagnosed, and FS-DSEK with secondary intraocular lens (IOL) sulcus fixation was planned. Institutional review board approval and the patient’s written informed consent were obtained. FS laser (60 kHz IntraLase; Abbott Medical Optics, Inc., Santa Ana, CA, USA) was used to prepare a deep horizontal lamellar interface in the donor cornea. The donor corneoscleral rim was placed in a Barron artificial anterior chamber (Katena Products, Inc., Denville, NJ, USA). The pressure in the artificial anterior chamber was assessed by palpation and titrated by controlling irrigation solutions. Intraoperative pachymetry measured the central thickness of the donor cornea as 560 lm. The raster spot pattern was used. Raster energy level of 1.8 lJ was employed to prepare for a horizontal lamellar cut at an intended depth of 390 lm. With the patient under retrobulbar anesthesia, cohesive ophthalmic viscosurgical devices (OVDs) were inserted through the recipient paracentesis site to maintain the anterior chamber. Through a 2.75-mm limbal incision at 9 o’clock of the limbus, a ?11.0 D three-piece IOL (Sensar AR40E, Abbott Medical Optics) was inserted into the anterior chamber and transsclerally sutured with 10-0 Prolene employing the ab externo approach [2]. The target refraction of the inserted IOL was emmetropic. An 8.0-mm-diameter circle of Descemet’s membrane and endothelium was stripped from the recipient cornea using a Price-Sinskey hook (Moria Inc., Doylestown, PA, USA). A 9.0-mm-diameter DPCD was inserted into the anterior chamber through a 5.5-mm limbal incision, and the end of the 10-0 nylon suture was pulled through the paracentesis site. Filtered air bubbles were injected into the recipient anterior chamber and pressed against the DPCD for 10 min. Two months postoperatively, uncorrected visual acuity (UCVA) was 20/400 OD, and the IOP was 17 mmHg OD. J. Y. Kim K.-H. Kim M. J. Kim H. Tchah Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Pungnap-2dong, Songpa-gu, Seoul 138-736, Republic of Korea

Late-onset Candida Keratitis after Descemet Stripping Automated Endothelial Keratoplasty: Clinical and Confocal Microscopic Report

To report clinical and confocal microscopy features of late-onset Candida albicans keratitis after Descemet stripping automated keratoplasty (DSAEK). We performed clinical and confocal scan on a patient who underwent DSAEK and phacoemulsification for Fuchs endothelial dystrophy and cataract. A 76-year-old woman who underwent uneventful DSAEK and phacoemulsification presented with white to cream deposits 3 months after DSAEK. Confocal microscopy showed a hyperintense deposit at the lenticule and interface. Confocal scan also disclosed intense haze and inflammation at the interface and clusters of hyperreflective round structures resembling epithelial cells within the interface area. No signs of hyphae-like structures were seen. Late-onset symptoms misled us into a bacterial chronic endophthalmitis diagnosis, and the patient was started on topical and systemic antibiotics. Despite intense antibiotic therapy, the patient developed severe endophthalmitis, so we performed anterior vitrectomy and the donor lenticule was removed. Microbiology results from the removed lenticule showed infection by C albicans. Antifungal therapy with systemic and topical voriconazole controlled the infection. Candida interface keratitis is possible after DSAEK. The posterior location of infected tissue poses diagnostic and therapeutic challenges. In our case, the late onset of the symptoms and not performing corneoscleral rim cultures delayed correct diagnosis. This is the first reported case of post-DSAEK Candida keratitis with confocal microscopy images. A hyperintense granular deposit was seen at the lenticule and interface with confocal microscopy. We also observed intense haze, granular round structures resembling epithelial cells, and hyperreflective needle-shaped material at the interface. No hyphae-like structures were seen with confocal imaging.

Characterization of the Cleavage Plane in Descemet's Membrane Endothelial Keratoplasty

To define the cleavage plane between Descemet's membrane (DM) and posterior corneal stroma in Descemet's membrane endothelial keratoplasty (DMEK) concerning its ultrastructural and immunohistochemical characteristics. Observational, consecutive case series. Fifteen corneoscleral buttons from donors 71.5±4.3 years of age stored in Optisol-GS and used for DMEK surgery in 15 consecutive patients. Endothelial cell-DM complexes (EDMs) and corresponding corneoscleral rims were investigated by transmission electron microscopy and immunohistochemistry using a panel of antibodies against adhesive matrix proteins. Ultrastructural and immunohistochemical characteristics of interface and cleavage plane between DM and posterior stroma. Connection between DM and corneal stroma was mediated predominantly by amorphous material of the interfacial matrix and projecting stromal collagen fibers. After DM stripping, the cleavage plane was located consistently between interfacial matrix and posterior stromal collagen lamellae, providing a largely smooth anterior EDM surface exposing the interfacial zone. Interindividual variations in amount and composition of the interfacial matrix resulted in variable degrees of EDM surface irregularities and variable staining patterns for adhesive matrix proteins such as fibronectin, vitronectin, amyloid P, osteonectin/secreted protein acidic and rich in cysteine (SPARC), fibulin-1, fibulin-2, fibulin-3, fibrillin-1, and keratoepithelin. The findings provide evidence for the existence of a physiologic cleavage plane between the interfacial matrix, the anteriormost adhesive zone of DM, and the corneal stroma, suggesting a relatively weak attachment that can be disconnected by mechanical forces. Interindividual variations in structure and composition of the interfacial matrix may provide an explanation for the variable attachment of EDM grafts to the recipients' corneal stroma and thus may affect the postoperative clinical outcome. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Combined chlorhexidine and PVP-I decontamination of human donor eyes prior to corneal preservation

The aim of this study was to report the efficacy of adding chlorhexidine to the protocol for decontamination of human donor globes prior to excision of corneo-scleral rims for future keratoplasty procedures. In 2005, chlorhexidine was introduced by our eye bank as an additional step in the protocol for decontaminating human donor globes. After 5 years, we prospectively evaluated the number of contaminations. Out of 2,891 globes included in our study, 2,663 globes were processed, of which 36 (1.4%) were considered contaminated. Seventeen contaminations (0.6%) were detected by culturing limbal swabs, directly after decontamination, eight (0.3%) by visible discoloration of the culture medium carrying a corneo-scleral rim, and eleven (0.4%) after inoculation of the culture medium on blood agar plates. Importantly, after 4 weeks of incubation, none of the aerobic and anaerobic cultures taken from the secondary 'transport medium' (dextran containing medium used to transport corneal tissue to the transplantation centre) showed microbiological growth. In conclusion, the combined use of 0.02% chlorhexidine and 0.5% povidone-iodine may allow decontamination of donor globes to a level at which the risk of tissue contamination at the time of transplantation is minimized, while corneal viability is preserved.

Femtosecond-UVA-riboflavin (FUR) cross-linking approach to penetrating keratoplasty and anterior lamellar keratoplasty

Purpose To introduce femtosecond laser wound design combined with riboflavin/ultraviolet light-A (UVA) collagen cross-linking at the wound for penetrating (PKP) and anterior lamellar keratoplasty (ALK). Primary outcomes were intraocular pressure (IOP in mmHg) at burst point for the PKP group, and tensile strength (kPa) until dehiscence for the ALK group. Methods Human corneoscleral rims ( N = 20) were mounted on artificial anterior chambers. PKP specimens underwent FUR, femtosecond laser-cut without cross-linking, or conventional corneal transplantation. PKP maximum burst IOP with progressive suture removal was assessed by a digital manometer, in triplicate and by three observers. ALK involved whole human globes ( N = 10) divided into three groups using a 200-micron, 8 mm diameter donor lenticule, with or without cross-linking. Cross-linked specimens were exposed to UVA light (3 mW/cm 2 irradiance, 3.4 J, 370 nm wavelength) for 30 min with 0.1% riboflavin (20% Dextran) applied every 2-min. ALK tensile strength was determined using a digital tensiometer. Results In PKP, burst IOP was 31.32 mmHg greater for corneas that underwent the UVA-riboflavin treatment than for those that did not ( p < 0.05). There was no significant relationship ( p = 0.719) established between cut design (femtosecond versus conventional). On multivariate analysis, there was a mean of 15.82 mmHg higher sustainable pressure for each stabilization suture present ( p < 0.0001). In ALK, specimens comprised of human donor and human recipient tissue combined with UVA-riboflavin therapy experienced the greatest level of adhesion strength (954.7 ± 290.4 kPa) as shown by the force required to separate the tissues, and compared to non-cross-linked specimens. Electron microscopy of ALK specimens showed non-fused and fused longitudinal cross-linked collagen fibers as well as bridges, densities, attachment plaques and primitive plasmalemmal densities. Conclusions Cross-linking effects of the FUR technique enable a stronger graft-recipient adhesion compared to conventional penetrating and anterior lamellar keratoplasty. Electron microscopy enabled visualization of cross-linked interface and potential bonding. The FUR approach may further lead to sutureless transplantation techniques in the future. Setting/venue ImagePlus Laser Eye Centre, Winnipeg, and University of Ottawa Eye Institute, Ottawa, Canada.

Comparação entre membrana amniótica com e sem epitélio como substrato para cultura de células epiteliais do limbo ex vivo

To evaluate the efficacy and ultrastructural aspects of human limbal epithelial cells cultured on amniotic membrane (AM) with and without epithelium. Limbal epithelial cell cultures were established from cadaveric cor neo-scleral rim explants derived from 6 different donors. The explants from each donor were placed under 3 different groups: on human preserved AM with epithelium (Group 1), AM deepithelialized with trypsin (Group 2) and control (Group 3). The epithelial cell migration was evaluated under phase contrast microscopy. After 15 days, the amniotic membrane with cells cultures were removed and submitted to scanning and transmission electron microscopy to check for epithelial migration and adhesion. All epithelial cell cultures from the controls grew over the botton of the culture plate wells until reaching confluence. Epithelial cultures grew over all but one denuded amniotic membrane. In the group amniotic membrane with epithelium, epithelial cell growing was observed only in 1 well. Using this model, denuded amniotic membrane appeared to be the best substrate for epithelial cell migration and adhesion comparing to amniotic membrane with epithelium. Removal of amniotic membrane epithelial seems to be an important step for establishing limbal epithelial cell culture on amniotic membrane.

Ocular herpes simplex virus type 1: is the cornea a reservoir for viral latency or a fast pit stop?

To present a review supporting and refuting evidence from mouse, rabbit, nonhuman primate, and human studies of herpes simplex virus type 1 (HSV-1) concerning corneal latency. More than 50 research articles on HSV-1 published in peer-reviewed journals were examined. Infectious HSV-1 has been found in mouse denervated tissues and in tissues with negative cultures from the corresponding ganglion. However, the different mouse strains have shown varied responses to different strains of HSV, making it difficult to relate such findings to humans. Rabbit studies provide excellent evidence for HSV-1 corneal latency including data on HSV-1 migration from the cornea into the corneoscleral rim and on the distribution of HSV-1 DNA in the cornea. However, the available methods for the detection of infectious HSV-1 may not be sensitive enough to detect low-level infection. Infectious HSV-1 has been successfully isolated from the tears of nonhuman primates in the absence of detectable corneal lesions. The recurrence of corneal ulcers in nonhuman primates before the appearance of infectious HSV-1 in tears suggests that the origin of the HSV-1 is the cornea, rather than the trigeminal ganglion. Human studies presented evidence of both ganglion and corneal latency. Understanding HSV-1 disease progression and the possibility of corneal latency could lead to more effective treatments for herpetic keratitis. However, it is unlikely that operational latency in the cornea will be definitively proven unless a new method with higher sensitivity for the detection of infectious virus is developed.

Limbal Allograft Transplantation Using Fibrin Glue

Limbal transplantation is now widely accepted as the treatment of advanced limbal stem cell deficiency. Herein, we describe a technique for harvesting thin limbal grafts from cadaveric corneoscleral rims and a sutureless method to secure the grafts to the recipient eye using fibrin glue. We report the results of fibrin glue-assisted keratolimbal allograft in 19 eyes of 16 patients, with the outcome measures being ocular surface stability, visual acuity, and postoperative complications. The results indicate that limbal allograft transplantation can be performed safely and successfully using only fibrin glue to secure the grafts. This can potentially improve surgical efficiency and patient comfort postoperatively.

A Surgical Technique for Donor Tissue Harvesting for Descemet Membrane Endothelial Keratoplasty

To create a reproducible and effective technique in donor tissue harvesting for Descemet membrane (DM) endothelial keratoplasty. A new method has been developed for the harvest of donor DM and endothelium. This method involves placement of a human corneoscleral rim in an artificial anterior chamber with removal of the anterior stroma with a Moria One microkeratome (Moria USA, Doylestown, PA). The residual stromal bed over the central cornea is removed by blunt dissection using a Barraquer sweep. A thin rim of posterior residual stroma permits easy donor button trephination and tissue manipulation. The risk of tearing through DM is minimal and may not preclude use in transplantation. This method allows relatively easy assessment of endothelial integrity before trephination. Optical coherence tomography evaluation revealed minimal stroma overlying DM and endothelium. Endothelial cell integrity of the harvested DM by this new harvest method was assessed using specular microscopy and demonstrated minimal loss after DM harvest. We presented a manual tissue harvest method for DM endothelial keratoplasty.

Can we overcome the challenges of sutures in lamellar keratoplasty?

Lamellar keratoplasty (LK) is a technique which can be followed for both tectonic and optical purposes. We describe a technique of sutureless anterior LK by fixing the donor lenticule to the recipient bed using fibrin glue. LK was performed in an eye with corneal opacity using the manual dissection method. The donor lenticule was cut with a microkeratome after fixing the corneoscleral rim in an artificial anterior chamber. The size of the donor lenticule was 8.5 mm and fixed to the recipient bed with fibrin glue. The surgical time was reduced significantly with this technique. There was an uneventful postoperative period during the follow-up of 12 months. Best corrected visual acuity improved from hand movement to 20/60. Thus, the use of fibrin glue for fixing the anterior lamellar lenticule is a viable option for both optical and anatomical purposes.

Influence of corneoscleral limbus incision on tear film stability after phacoemulsification

目的 探讨角巩膜缘切口对白内障超声乳化术后泪膜变化的影响.方法 研究为临床疗效评价的病例对照研究.收集2006年7月-2008年12月行小切口白内障超声乳化及人工晶状体(IOL)植入术的年龄相关性白内障患者128例219眼;年龄61～87岁,平均年龄(66.1±12.1)岁.按信封法随机将患者分为3组,其中角巩膜缘切口组42例69眼,透明角膜切口组45例70眼,巩膜隧道切口组41例80眼.各组资料的人口统计学特征差异无统计学意义(P>0.05).在术前第1天,术后第1、2、7、30、90天对各组患者进行干眼症状评分、Schirmer试验(SIt)、泪膜破裂时间(BUT)和角膜荧光素染色(FLS)4项指标的检测.结果 角巩膜缘切口组、透明角膜切口组和巩膜隧道切口组在检测的各时间点(F=110.51,P=0.00)干眼症各组临床评分(F=99.45,P=0.01)的差异均有统计学意义.角巩膜缘切口组干眼症临床评分在手术后14d逐渐下降,各时间点的临床评分与术前相比差异均有统计学意义(P 0.05),而透明角膜切口组手术后14d的BUT值最低.手术后1d角巩膜缘切口组的SIt值达高峰,第1～14天逐渐降低,各组间的差异均有统计学意义(P 0.05).结论 角巩膜缘切口对泪膜的稳定性影响小,是干眼症高危患者白内障超声乳化术较为理想的选择。